There was a study done some time ago that showed that people who negatively review something appear to be more intelligent than those who positively review the same thing.
This is probably the case here even though I don't know who Maciej is or what Rails app he's actually written. I think you should use a tool you're reviewing for a project before making up your mind about it.
The study is discussed in a blog post here, http://bobsutton.typepad.com/my_weblog/2006/08/brilliant_but..., the original reference is Teresa Amabile, "Brilliant but Cruel: Perception of Negative Evaluators," Journal of Experimental Social Psychology, 19 (1983), 146-156.
This is probably the case here even though I don't know who Maciej is or what Rails app he's actually written. I think you should use a tool you're reviewing for a project before making up your mind about it.